Rats Be Gone
Logo for Remove Rats campaign (credit: Hawaii.gov)
Irrespective of size, islands are surprisingly susceptible to invasive species. Whether released goats and donkeys on the Galapagos; feral foxes, rabbits, cats, camels, and many plant species in Australia; mosquitoes on Hawai'i; or rats infesting any island you wish to mention, the impacts inflicted on the endemic species and an island's ecology are massive.
In most ecosystems, the apex predator is a carnivore such as a wolf, tiger, shark, bear, or killer whale. These large creatures affect the entire structure of the ecological system by praying on weaker animals and keeping everything in a balanced state. If the apex predator is eliminated from the landscape, everything degrades. Restoration of Yellowstone once wolves were released, after being extinct for nearly a century, shocked researchers at how rapidly the landscape and its species populations became re-balanced.
What would happen to a landscape where a native predator never existed? It is fully displayed on remote islands, solely inhabited by migratory birds and strange plants, when rats were unintentionally introduced by boats and shipwrecks. Populations of nesting birds, an island's endemic plants, insects, and turtles were savaged, by predation from the rats and in some cases eaten to extinction.
However, that situation can be reversed with dedicated projects to eliminate the rats, rabbits, cats, and other invasive species by implementing eradication programs. Each recovery effort requires island specific characteristics but the results can be remarkable on from coastal California islands, to the tropics, and even sub-Antarctic islands in the southern ocean. Two hopeful case studies of such restoration initiatives are worth viewing. WHB